/*
 * Copyright (C) 2023 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.intentresolver.inject

import android.os.Handler
import android.os.HandlerThread
import android.os.Looper
import android.os.Process
import dagger.Module
import dagger.Provides
import dagger.hilt.InstallIn
import dagger.hilt.components.SingletonComponent
import javax.inject.Singleton
import kotlinx.coroutines.CoroutineDispatcher
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.SupervisorJob

// thread
private const val BROADCAST_SLOW_DISPATCH_THRESHOLD = 1000L
private const val BROADCAST_SLOW_DELIVERY_THRESHOLD = 1000L

@Module
@InstallIn(SingletonComponent::class)
object ConcurrencyModule {

    @Provides @Main fun mainDispatcher(): CoroutineDispatcher = Dispatchers.Main.immediate

    /** Injectable alternative to [MainScope()][kotlinx.coroutines.MainScope] */
    @Provides
    @Singleton
    @Main
    fun mainCoroutineScope(@Main mainDispatcher: CoroutineDispatcher) =
        CoroutineScope(SupervisorJob() + mainDispatcher)

    @Provides @Background fun backgroundDispatcher(): CoroutineDispatcher = Dispatchers.IO

    @Provides
    @Singleton
    @Broadcast
    fun provideBroadcastLooper(): Looper {
        val thread = HandlerThread("BroadcastReceiver", Process.THREAD_PRIORITY_BACKGROUND)
        thread.start()
        thread.looper.setSlowLogThresholdMs(
            BROADCAST_SLOW_DISPATCH_THRESHOLD,
            BROADCAST_SLOW_DELIVERY_THRESHOLD
        )
        return thread.looper
    }

    /** Provide a BroadcastReceiver Executor (for sending and receiving broadcasts). */
    @Provides
    @Singleton
    @Broadcast
    fun provideBroadcastHandler(@Broadcast looper: Looper): Handler {
        return Handler(looper)
    }
}